Jonathan Phelps, a member of the group that has been spreading its anti-gay message for 15 years

Preacher Fred Phelps' anti-gay campaign is testing the limits of the US constitutional commitment to free speech.

His protests could hardly be better designed to provoke outrage among the great majority of Americans.

The 76-year-old head of the Westboro Baptist Church has over the past year been using military funerals to spread his message that soldiers' deaths in Iraq are God's punishment against America for tolerating homosexuality.

Reverend Fred Phelps is used to being in the crosshairs of US lawmakers. Dozens of states have either passed or are considering passing laws aimed at restricting his picketing of soldiers' funerals.

On Wednesday, Congress approved legislation barring demonstrators from disrupting military funerals at national cemeteries.

Family group

Fred Phelps is the head of the Westboro Baptist Church based in Topeka, Kansas. The extremism of his views can be gauged by the name he has given his website - godhatesfags.com.

His church is small, consisting of some 75 members, mostly from his extended family. It is not allied to any other church group.

Yet, despite this, it has managed to get itself heard across the nation. The group has disrupted funerals up and down the country by waving signs saying "Thank God for Dead Soldiers" and shouting insults at the bereaved.

Most members of the small church belong to Phelps' extended family

In a recent interview with the BBC, Mr Phelps' daughter Shirley Phelps-Roper explained the group's motives.

"We're trying to help get this nation to connect the dots - you turn the country over to fags and now those soldiers are coming home in body bags," she said.

So far, nine states have approved laws that impose restrictions on demonstrations at funerals and burials. More than 20 other states are considering similar legislation.

The Respect for America's Fallen Heroes Act passed by both houses of Congress on Wednesday now only needs President George W Bush's signature.

It would bar protests within 90 metres (300 feet) of the entrance of national cemeteries, including Arlington, outside Washington DC, and within 45 metres (150 feet) of a road into the cemetery from an hour before to an hour after a funeral.

Freedom of speech

The debate over the church's actions has also taken in the nature of freedom of speech and whether or not state measures infringe on the constitution's first amendment guaranteeing free speech.

The Patriot Guard Riders provide a "shield" at the funerals

Civil liberty groups have argued that such measures are vulnerable to challenge.

In response to the demonstrations, a motorcycle group including many veterans, has been appearing at military funerals to pay respects to the fallen service members and to drown out the sound of the Phelps' group's protests.

"We turn up to the funeral if we have been invited by the family," Kurt Mayer of the motorcycle group Patriot Guard Riders, told BBC World Service radio recently. "We block the view of vulgar and offensive signs."

Mr Mayer acknowledged that one of the great ironies is that these are soldiers who have died protecting freedoms, such as the freedom of speech, yet he and his Harley Davidson-driving comrades form human shields between the mourners and the protesters to block the signs and insults.

"You do have the right to say pretty much what you want to in America - no matter how vulgar and offensive it is," Mr Mayer told the BBC.

But he says that "any sensible person would agree that a funeral is not the correct time or place to make a political or religious statement."

National attention

Mr Phelps and his family have been travelling the country denouncing homosexuality since the early 1990s. They have picketed the funeral of Aids victims and published a newsletter denouncing gays.

But it was not until after the brutal death of an openly gay man Matthew Shepard in Wyoming in 1998 that the group really gained national attention.

Matthew Shepard's death shocked the country

Shepard's death deeply shocked America. He was a university student who accepted a lift from two men in a bar in Laramie. They drove him to a field, beat him savagely, tied him to a fence and left him for dead.

Shortly afterwards, Mr Phelps tried to have a 6ft granite monument to Shepard installed in a park in the victim's hometown, stating that he had entered hell for "defying God's warning".

He then tried to donate it to a courthouse, which similarly resisted his overture.

The preacher has said he will abide by the Congressional measure if it becomes law. But legal challenges cannot be ruled out.

Mr Phelps is a former lawyer and a number of his 13 children are practising lawyers.